https://scidar.kg.ac.rs/handle/123456789/13385 Fri, 08 May 2026 21:55:49 GMT 2026-05-08T21:55:49Z https://scidar.kg.ac.rs/handle/123456789/23080 Title: Synergistic interactions of a copper(II) complex and a natural extract with HSA with ibuprofen and eosin Y Authors: Kesić, Ana; Gigić, Andrija; Bogojeski, Jovana; Stevanović, Dragana; Bugarinović, Jovana Abstract: Abstract: The interactions of a copper(II) complex and a natural extract from Salvia pratensis root with human serum albumin (HSA) were studied using fluorescence spectroscopy, focusing on their synergistic effects. Binding studies in the presence and absence of site markers, ibuprofen and eosin Y, assessed binding affinity and potential sites. The copper(II) complex showed moderate interaction with HSA, while the extract had stronger binding. The combined system exhibited enhanced, marker-independent binding, indicating a synergistic effect. These findings suggest the extract influences the interaction between the copper complex and HSA, affecting its transport and biodistribution. Thu, 01 Jan 2026 00:00:00 GMT https://scidar.kg.ac.rs/handle/123456789/23080 2026-01-01T00:00:00Z https://scidar.kg.ac.rs/handle/123456789/23079 Title: CATALYTIC ACTIVITY OF GREEN-SYNTHESIZED AgNPS IN THE REMOVAL OF DYE POLLUTANTS FROM WASTEWATER Authors: Kesić, Ana; Sreckovic, Nikola; Mihailovic, Vladimir; Marković, Katarina; Grujović, Mirjana Abstract: Abstract: Dye-containing wastewater represents a serious environmental problem due to the toxicity and persistence of synthetic dyes. In this study, the catalytic activity of silver nanoparticles (AgNPs) obtained by green synthesis using Agrimonia eupatoria L. plant extract as a reducing agent was investigated. The catalytic performance of AgNPs was evaluated through the reduction of Congo red in the presence of NaBH₄, monitored by UV–Vis spectrophotometry. The results demonstrated efficient catalytic degradation of the dye, with a calculated pseudo-first-order rate constant of k′ = 0.0299 min⁻1. The biogenic AgNPs exhibited high catalytic efficiency, indicating their strong potential for application in wastewater treatment. Thu, 01 Jan 2026 00:00:00 GMT https://scidar.kg.ac.rs/handle/123456789/23079 2026-01-01T00:00:00Z https://scidar.kg.ac.rs/handle/123456789/22994 Title: NUMERICAL ANALYSIS OF ROTATION STEP AND TRACKING STRATEGY IN FLAT-PLATE SOLAR COLLECTORS: THERMAL PERFORMANCE AND COST-EFFECTIVENESS Authors: Kowalik, Robert; Nešović, Aleksandar Abstract: This study presents a numerical analysis of Sun-tracking strategies for flat-plate solar collectors, with emphasis on the influence of discrete rotation step size and control strategy on thermal performance. Two distinct control approaches were examined: absolute Sun tracking (aSAT), which continuously aligns the collector with the solar position, and relative Sun tracking (rSAT), which performs incremental angular adjustments. A total of sixteen configurations were simulated, combining both tracking strategies with eight discrete rotation step angles ψ = {1°, 2°, 5°, 10°, 15°, 30°, 45°, 90°}. Simulations were conducted using EnergyPlus 9.6 coupled with a custom Python interface, allowing one-minute resolution control of collector orientation. This framework enabled a detailed assessment of the effect of actuator precision on incident solar radiation and useful thermal gain. A temperature-dependent efficiency model, based on the Hottel–Whillier formulation, was implemented to account for heat losses as a function of ambient temperature and irradiance. Results demonstrate that increasing the rotation step ψ leads to a nonlinear decrease in collected energy, with energy losses reaching approximately 9% when ψ increases from 1° to 90°. The optimal balance between performance and mechanical simplicity was found for ψ = 10–15°, where the system retained over 90% of the energy yield of a continuously tracking collector. Absolute tracking (aSAT) achieved up to 17% higher daily energy gain compared to relative tracking (rSAT), especially for fine rotation steps. Although economic aspects were not included, the results provide clear design guidance for optimizing Suntracking mechanisms in flat-plate solar thermal systems. The developed numerical framework may support further experimental validation and the integration of tracking algorithms in low-energy and near-zero-energy buildings (nZEBs) under varying climatic conditions. Thu, 01 Jan 2026 00:00:00 GMT https://scidar.kg.ac.rs/handle/123456789/22994 2026-01-01T00:00:00Z https://scidar.kg.ac.rs/handle/123456789/22881 Title: NUMERICAL SIMULATION OF AORTIC DISSECTION: EVALUATING VIRTUAL SURGICAL INTERVENTIONS FOR IMPROVED HEMODYNAMIC OUTCOMES AND PERSONALIZED TREATMENT PLANNING Authors: Saveljic I.; Djukic, Tijana; Tomasevic, Miloje; Filipovic, Nenad Abstract: Aortic dissection is a severe clinical condition that demands a thorough understanding of the interactions between the true and false lumens. In this study, numerical simulations were performed for two patients, generating two preoperative and two postoperative models. The analyses were carried out using the PAKSF solver, a specialized tool for fluid–structure interaction problems. The objective was to evaluate the influence of virtual surgical interventions by examining essential hemodynamic parameters, including shear stress, pressure, and flow velocity in both lumens. The findings indicate that virtual surgical modeling can serve as a valuable tool for surgical planning, providing improved insight into post-intervention hemodynamic alterations. Moreover, this methodology supports patient-specific treatment strategies, contributing to optimized outcomes. Overall, the results highlight the potential of numerical simulations in clinical practice, particularly for the management of complex vascular disorders. Wed, 01 Jan 2025 00:00:00 GMT https://scidar.kg.ac.rs/handle/123456789/22881 2025-01-01T00:00:00Z